Why are they closed so early in October? Why is everything worth seeing closed after Columbus day? I am coming the 3rd weekend in Oct for the first time and there is so much i can't do, see or experience.

It is most likely because a large area of the museum is outdoors, so they probably close due to the cold.

My understanding is that everything closes after labor day.

The old saying for the Adirondacks is summer starts and finishes on the 4th of July. By the time October rolls around the temperatures at night are sometimes in the fifties a lot of these places make the majority of their income from June to the end of September. Like for instance our motorcycle riding season didn't start to the first week of June but if we dare to we rode our bikes right up into November October starts the beginning into November of the peak Leaf changing season which brings in tons of tourists every year and we cannot forget Lake Placid for the winter events they have each year. You may also want to try bed and breakfasts as there are a lot and a Adirondacks